Of the world's major languages, Arabic is one of the most notorious for regional dialectical differences. In recent times, an official dialect known as Modern Standard Arabic has been developed for use throughout the Arabic-speaking world. On a less-than-official level, however, the colloquial dialects are still problematic, and travelers often strive to learn as closely as possible the dialect of the region to which they will be traveling.
Egyptian Arabic is especially useful, both for those whose destination is Egypt and also as an all-purpose dialect, since a great many films, radio, and television programs are produced in Egypt, and consequently the dialect is widely understood throughout the Arabic-speaking world.
Although there are regional dialects within Egypt itself, the dialect of Cairo is considered Standard Egyptian Colloquial Arabic, and it is this dialect you will be learning on the Pimsleur Egyptian Arabic.